Determination of the weight and balance of an aircraft is a critical safety operation. If operated outside of its weight and balance limits an aircraft may become unstable and unsafe.
It is known to perform weight and balance calculations which are calculated from the estimated mass of passengers, baggage and fuel etc. However these calculations are time consuming and generally give a conservative estimate that may leave the aircraft under loaded.
Automated systems that measure the weight and balance of an aircraft by measuring shock absorber pressure in the aircraft landing gear when the aircraft is loaded are also known. However, these measurements can be inaccurate due to static friction or ‘stiction’ caused by seals and bearings in the shock absorber.
One strategy to overcome the stiction is to provide a ‘bump’ to the shock absorber by increasing and decreasing the internal pressure in the shock absorber slightly before performing the measurement.
However known systems for providing a shock absorber bump have the potential to decrease the reliability of the shock absorber.